Aion FX Argus Fuzz (Roland Double Beat)

[gila_crisis]

New DIY fuzz on the bench: the Roland AD50 Double Beat fuzz, built thanks the Aion FX Argus pcb.

I did few mods to have more bass and gain range available. I reworked a bit the mid scoop preset, and especially tweaked a lot the Sinus tone preset as it was cutting way to many highs for my taste, sounding too dark and dull, now it's a super cool Mid Boost tone preset!
I played also with the transistors and came up with this cocktail of BC107b, BC109c and MPSA13 (but may try out a MPSA14 in Q3 for even more output gain).
It's a very cool fuzz, that goes from low gain overdrives up to wall of sound mayhem.
The mid scoop tone setting instead of the Triangle tone preset found in the original circuit is a very clever idea, and the added input gain and body/bass control added by Aion FX make the pedal very versatile (actually control array is very similar to the Basic Audio Duplex).

Highly recommended to anybody who wants to try out something different than the usual Big Muffs, Fuzzs Face or Tone Benders.

Mods:
Sustain pot 20k
C2 1uF
C6 100nF
C10 22nF (minor change as I couldn't find a 18nF)
C11 4.7nF
C12 10nF
R14 jumper
R15 24k
R19 70k (I put a 220k in parallel of the original 150k, together with C11 it makes the Sinus preset brighter and more into Mid Bosst range!)
Q1 BC107B
Q2 BC109C
Q3 MPSA13

 

[Feral Feline]

Great looking build!


Many thankages for sharing your mods.

 

[gila_crisis]

Thanks! I got the enclosure already colored from Banzai Music. It's a cool black sparkling.
Here also a demo of the pedal:

On some setting it can self oscillate! Also after I shoot the video, I did tweak a bit R19 and went down to about 70k: this way the Sinus position becomes a mid boost: highly recommended mod!

 

[comradehoser]

Thanks! I got the enclosure already colored from Banzai Music. It's a cool black sparkling.
Here also a demo of the pedal:

On some setting it can self oscillate! Also after I shoot the video, I did tweak a bit R19 and went down to about 70k: this way the Sinus position becomes a mid boost: highly recommended mod!

Just built this with your mods. Socketed all changes so I can compare, but I fired this up last night, and I don't think I need to.

Thank you for helping me find my new favorite fuzz.

It is a ripper, and very useable across all dial sweeps. The switch makes a big difference, too. Haven't yet discovered the self-oscillation, though--maybe because I didn't have the 20k pot for sustain. Reminds me of a more musical version of the Mountainking Megalith. I might build 2!

 

[comradehoser]

Discovered the self-oscillation (input below 9:00) and can do almost high-gain chugs on this. It is a super versatile, super fun circuit